v3.25.4
Fair value of assets and liabilities - Methods applied in determining fair values of financial assets and liabilities (carried at amortised cost) (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks € 21,204 € 21,770
Loans and advances to customers 727,733 683,611
Deposits from banks 18,517 16,723
Customer deposits 721,373 691,661
Debt securities in issue 151,231 142,367
Subordinated loans 18,100 17,878
Financial liabilities    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks 18,308 16,499
Customer deposits 721,097 691,287
Debt securities in issue 152,391 142,905
Subordinated loans 18,722 18,357
Financial liabilities 910,519 869,048
Financial liabilities | Level 1    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks
Customer deposits
Debt securities in issue 84,506 79,254
Subordinated loans 18,368 17,968
Financial liabilities 102,874 97,221
Financial liabilities | Level 2    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks 9,162 8,208
Customer deposits 82,665 61,916
Debt securities in issue 64,028 61,651
Subordinated loans 354 389
Financial liabilities 156,208 132,164
Financial liabilities | Level 3    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks 3,745 3,943
Customer deposits 17,433 46,984
Debt securities in issue 3,857 2,000
Subordinated loans
Financial liabilities 25,035 52,927
Financial liabilities | Carrying Amount    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks 18,517 16,723
Customer deposits 721,373 691,661
Debt securities in issue 151,231 142,367
Subordinated loans 18,100 17,878
Financial liabilities 909,221 868,630
Financial liabilities | Carrying amount presented as fair value    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Deposits from banks 5,401 4,348
Customer deposits 620,999 582,387
Debt securities in issue
Subordinated loans
Financial liabilities 626,401 586,735
Financial Assets    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks 21,141 21,766
Loans and advances to customers 709,405 667,410
Securities at amortised cost 52,796 48,303
Financial assets 783,342 737,479
Financial Assets | Level 1    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks
Loans and advances to customers
Securities at amortised cost 47,722 42,871
Financial assets 47,723 42,871
Financial Assets | Level 2    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks 14,722 15,614
Loans and advances to customers 12,782 18,626
Securities at amortised cost 2,381 2,908
Financial assets 29,885 37,149
Financial Assets | Level 3    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks 3,366 2,957
Loans and advances to customers 678,392 630,493
Securities at amortised cost 2,692 2,523
Financial assets 684,450 635,973
Financial Assets | Carrying Amount    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks 21,204 21,770
Loans and advances to customers 727,733 683,611
Securities at amortised cost 53,867 50,273
Financial assets 802,804 755,655
Financial Assets | Carrying amount presented as fair value    
Disclosure of fair value measurement of assets and liabilities [Line Items]    
Loans and advances to banks 3,053 3,195
Loans and advances to customers 18,231 18,291
Securities at amortised cost
Financial assets € 21,284 € 21,486